Center break thrust type switch



Dec. 20, 1966 A. Fo'rl CENTER BREAK THRUST TYPE SWITCH 5 Sheets-Sheet 1 Filed April 2, 1965 Dec. 20, 1966 Filed April 2, 1965 1&5..

A. FOTI CENTER BREAK THRUST TYPE SWITCH 5 Sheets-Sheet 2 IN VEN TOR.

/9/95/17 Fdr/ Dec. 20, 1966 A. FOTl CENTER BREAK THRUST TYPE SWITCH Filed April yz, 1965 5 Sheets-Sheet 3 United States Patent 3,293,387 CENTER BREAK THRUST TYPE SWITCH Arem Foti, Greensburg, Pa., assiguor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Apr. 2, 1965, Ser. No. 444,990 Claims. (Cl. 20G-48) The instant invention relates to switches and more particularly to a disconnecting switch of the center break thrust type, which novel design requires substantially less phase to phase spacing and physical clearance spacing than conventional switches of the equivalent voltage-current ratings.

Disconnect switches are well known in the electrical power distribution field and are typically employed for the purpose of isolating a section of the distribution network to enable maintenance or other personnel to approach and work upon equipment in the isolated section of the network without fear of any harm befalling them due to energization of the line. Conventional disconnect switches are typically comprised of a supporting structure upon which are mounted suitable insulator columns for receiving the jaw and hinge assemblies of the disconnect switch. The hinge assembly typically rotatably operates a switchblade movable in a vertically aligned arcuate path for making selective engagement with the switchblade jaw. In such disconnect switch designs, the switchblades have lengths of up to 16 or 17 feet for eXtra high voltage applications and hence require a substantial amount of overhead clearance, as well as a suitable phase to phase clearance for disconnect switches of each phase. Disconnect switches having switchblades which are rotatably mounted for tracing an horizontally aligned arcuate path typically have switchblades of a length in the range of 8-10 feet. Disconnect switches of this general type require increased phase to phase spacing as compared with disconnect switches having switchblades moving in a vertical plane.

The primary object of the instant invention is to provide a novel switchblade assembly which requires substantially less phase to phase and overhead clearance as compared with switches having the identical ratings.

The instant invention is comprised of a center break thrust type disconnect switch having first and second switchblade members mounted upon insulator columns with the blade member always being in the horizontal position although moving toward closure within a vertically aligned plane. Each switchblade assembly is comprised of first and second connecting links suitably coupled to the disconnect switch insulator columns at first ends thereof and pivotally linked to the switchblade at second ends thereof. At least one of the insulator columns is rotatable and is preferably engageable with one of said links through a bevel gear arrangement for moving the switchblade. The switchblades move in unison and in addition to being horizontally aligned are substantially parallel to one another, moving toward engagement or toward separation with one another with a thrust type action. The arrangement substantially minimizes the total overhead clearance required while providing all other advantages of disconnect switch structures having substantially identical voltage and current ratings.

As an alternative embodiment, the switchblades may be mounted so as to move in a horizontally aligned plane with the sidewise clearance of such structures requiring substantially less spacing than horizontally moving disconnect switches of equivalent ratings.

It is therefore one object of the instant invention to provide a novel disconnect switch assembly.

Another object of the instant invention is to provide a novel disconnect switch assembly employing a center break structure comprised of first and second switchblades.

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Still another object of the instant invention is to provide a novel disconnect switch assembly employing a center break structure comprised of first a-nd second switchblades wherein the switchblades move toward and away from engagement in a thrust type movement.

Still another object of the instant invention is to provide a novel disconnect switch assembly employing a center break design comprised of first and second switchblades mounted to the disconnect switch insulator columns by means of suitable linkages which maintain the switchblades parallel to one another in all positions of switchblade movement.

These and other objects of the instant invention will become apparent when reading the accompanying description and drawings in which:

FIGURE l shows an elevational view of a disconnect switch designed in accordance with the principles of the instant invention.

FIGURE 2 is an elevational view of an alternative embodiment of the instant invention.

FIGURE 3 is an elevational view of still another preferred embodiment of the instant invention.

FIGURE 3a shows a top view of the disconnect switch of FIGURE 3,

FIGURE 4 is a sectional view of a bevel type gear arrangement.

Referring now to the drawings, FIGURE 1 shows a disconnect switch assembly in which the blade members move in a vertical plane during switch operation. The assembly 10 of FIGURE 1 is comprised of a supporting structure 11, having rst and second vertically aligned supporting columns 12 and 13 mounted to any suitable foundation and a switch base 14. The base 14 supports first and second insulating columns 15 and 16, respectively. Each of the insulating columns 15 `and 16 are rotatably mounted to the base structure 14, being mounted on rotatable bearing assemblies 15a and 16a, respectively. The insulator columns are rotatable inunison by means of the operating member 17 which may be moved either toward the left or toward the right, as shown by arrows 19 and 18, respectively. The openating lever 17 is coupled to the rotatable bearing shafts 15a and 16a by suitable levers 20 and 21, coupled at first ends thereof to the connecting link 17 by pins 22 and 23, respectively. The opposite ends of levers 20 and 21 are rigidly secured to shafts 15a and 16a and to the insulating columns 15 and 16 at the lower ends thereof so as to translate the rotational motion of one rotating insulator 15 into rotational motion of the other rotating insulator 16 through the action of levers 20 and 21 and link 17. The rotational motion is employed for the purpose of operating the disconnect switchblades toward the opening or closing directions, in a manner to be more fully described.

The upper ends of insulator columns 15 and 16 are provided with suitable hinge assemblies 24 and 25 which are pivotally connected to one end of a blade connecting link 26 and 27 `at 28 and 29, respectively. The opposite ends of 'links 26 and 27 are pivotally coupled to switchblades 30 and 31 Lat 32 and 33, respectively.

The hinge assemblies 24 and 25 are further provided with suit-able fastening rneans (not shown) for rigidly securing one end of a bus 34 and 35 to the hinge assem- !blies. Each bus 34 and 35 is further provided with a second hinge assembly 36 and 37, respective-ly, for pivotally linking thereto `a second switchblade connecting link 38 and 39 at 40 and 41, respectively. The opposite end of these second connecting linrks 3S Iand 39l are coupled near the rear end of switchblades 30' and 31 at 42 and 43, respectively. Links 26 and 38 are interconnected by suitable means `so that movement of drive link 26 will cause the linkage vsystem 26 and 28` to move with blade 30 in pantograph manner. Suitable bus support assemblies 44 land 45 are provided to hold hinges 24' and 2S stationary during rotation of insulators 15 and 16. Each of these support assemblies is comprised of a suitable base structure 46 and 47 upon which is mounted an insulating column 48 and 49, respectively, in order to suitably support land maintain each bus 34 and 35 in the positions as shown in FIGURE 1. Y

The forward end 30a of switchblade 30 is tapered and the forward end 31m of switchblade 31 is provided with a tulip clip in order to facilitate electrical engagement between the switchblade assemblies.

The solid line designations of switchbla-des 30 and 31 show the switchblade in the fully open positions. In order to close the disconnect switch, insulator columns 15 and 16 are rotated in unison with the connecting link 17 moving in the direction shown by arrow 19, for example.

These insulator columns couple their rotational motionv through suitable bevel gearing arangements (to be more fully described) to the links 26 and 27, causing them to rotate in a direction shown by arrows 50 and 51. In moving towlard the closing direction, .the maximum vertical position attained by the switchblades is shown by the ldotted line configurations 30 and 31', respectively. The switchblade members continue to move toward one another so that, as they are about to mutually engage one another they do so in a thrust type motion, thereby providing suitable sliding engagement between the tapered front end 30a and the tulip clip 31a. These elements occupy the dotted Aline positions 30a and 31a" when the disconnect .switch is in the ful-ly engaged position.

With the arranement of FIGURE 1, the blade members 30 and 31 are located immediately atop their associated buses 34 and 35, respectively, with the disconnect switch in the fully open position. Blades 30 and 31, in addition thereto, Iare substantially in alignment with their associated buses. This .arrangement uses the bus structures 34 and 35 to advantage by depending upon the buses for some support of the disconnect switch blade assemblies, 11h-us requiring a minimum of two insulator columns 15 and 16, respectively. The maximum vertical position attained by the switch is shown by the dotted line congurations 30 and 31'. This position require less than one-fourth the clearance of conventional vertical break switches having the same voltage ratings. Since the blades 30 and 31 move in a vertical plane, there is no need whatsoever for providing any increasing horizontal or phase clearance between adjacent switches.

It should be noted that in the closed position the current path extends through bus 34, hinge 24, link 26, blade 30, blade 31, link 27, hinge 25 Iand conductor 35, it being noted that links 26 land 27 are current-carrying members. 'The links 38 and 39 may be current-carrying members, but the main path of 'current ilow is through the links 26 and 27.

FIGURE 2 shows a disconnect switch assembly 1G" which is quite similar to that shown in FIGURE 1, with the exception of providing additional insulating columns 52 and 53 for supporting land carrying the weight of the blade assemblies so as not to depend -upon the buses 34 and 35 to act as the torque stabilizing means.

The insulator columns 52 and 53 `serve the same purpose as the bus support .assemblies 44 and 45 of FIGURE 1. In this arrangement lighter weight insulator columns 15' and 16 may 'be used as the rotating insulators to impart motion to the blade members during switch operation. The switchblade assembly of FIGURE 2 operates in the same manner `as that shown in FIGURE 1 with rotation -of the insulator columns 'being translated into blade motion through a bevel gearing arrangement to be more fully described.

FIGURE 3 shows a disconnect switch assembly 10 which is substantially identical to that shown in FIGURE 2 with the exception that the switchblade members are arranged to move in a horizontal plane. With the arrangement 10 no provision for increased vertical clear- 4 ance is required. Only relatively `small additional horizontal or phase distance may be required due to the double blade structure, if encroachment on phase clearance is not tolerable during the interim operating position 31 of blade 31, for example.

In the arrangement 10 of FIGURES 3 and 3a, the connecting link (which is preferably a pair of links) 26, is pivoted at 28 to the hinge assembly 24 and has its opposite end pivoted at 32 to blade 30. Link 38 is pivoted in a like manner and the entire linkage system Ibehaves as previously described for FIGURE 1. The pad 34 is suitably provided for the purpose of coupling the incoming bus 34 (not shown) to the switchblade 30 while the pad 35 cou-ples the incoming bus 35 (also not shown) to switchblade 3-1. The bevel gearing arrangement (to be more fully described) causes the switchblades 30 and 31 to rotate in a horizontal plane, `as shown by arrows 60 and 61, so that the blades 30 and 31 move from the fully open position through the intermediate position 31)' 31 to the closed position 30"31. 'Ilhe intermediate positions 30 and 31 are those positions which dictate the maximum phase clearance required for a switchblade structure in which the blades 39 and 31 move in a horizontal plane.

Although the drawings show the blades moving in arc paths 60 and 61, the 'blades may be 4arranged to move in the opposite direction. F or instance, blade 31 may be rotated in the direction shown by arrows 62, occupying an intermediate position 31". In the latter case, blade 30 would be arranged to rotate in a direction such that its tapered contact end is always facing the tulip clip of blade 31.

FIGURE 4 shows a bevel gear arrangement 7) which may be employed for rotating the switch blade assemblies of the instant invention. The arrangement is comprised of lever 20 coupled to connecting link 17 by suitable pin means 22. The opposite end of lever 2i) is secured to the rotating insulator `column 15. Shaft 81 is attached to the top of insulator column 15 and passes through the lower end of the hinge assembly 24 where it is rigidly secured to a rst bevel gear 71. The hinge assembly 24 is provided -with lirst and second vertically extending arms 72 and 73 which suitably support a shaft. The shaft 74 supports the links 26 which are keyed to Ishaft 74 together with a vertically aligned gear member 75. A suitable spacer 76 acts to rigidly position the links 26 and gear 75.

By moving connecting link 17 in the direction shown by Iarrow 18, this rotates insulator column 15 in the direcftion shown by arrow 77, causing bevel gear 71 to rotate in the same direction. This causes gear 75 and hence shaft 74 and links 26 to rotate in a direction shown by arrow 79. Movement of connecting link 17 in the direction shown by arrow 19 rotates insulator column 15 and gear 71 in the direction shown by arrow 78, causing sha-ft 74, gear 75 and links 26, 26 to rotate in a direction shown by arrow 80. The rotational relationship 'between gears 71 and 75 may be reversed if desired by positioning gear 75 immediately adjacent the left-hand link 26 as opposed to the righohand link to which it is adjacent in FIGURE 4. Whereas the lbevel geared arrangement of FIGURE 4 is suitable for providing the desired motion, it should be understood that any other type of linkage may be employed to provide suitable blade motion.

All lof the switchblade assemblies 10, 10 and 10 have essentially ythe same blade motion and contact engagement. With the parallel-thrust type contact motion the contact structures (wherein a tapered rod end is thrust into a set of cooperating lingers such as a tulip clip type) are tolerable to considerable variation in center line spacing of the insulator column. Relatively low operating elort is required to move the blade members from open to close position, into and out of contact engagement.

Some of the advantages of the instant invention are:

Substantial minimizing of phase spacing and overhead clearance, together with the associated advantage of the minimizing of real estate and space requirements for assembly and operation of the disconnect switch.

The economic advantage of using a two-insulator-perpole switch instead of the customary three-insulator-perpole switch, when the design of FIGURE l is employed.

The contact structure of the switch is tolerable to large variations in insulator center lines.

The low -operating effort required has the advantage of employing simpler, lower cost mechanisms for operating the switch.

Blow-open effect due to electromagnetic forces under short-circuit conditions is eliminated by the in-line or straight-through contact arrangement when the switch is closed.

In the operation of extra high voltage rating disconnect switches, such as switches of the 500 or 700 kv. class wherein the blades move in a horizontal plane, no counterbalancing structures are required. While the blade mem- -bers which are arranged to move in a vertical plane may require moderate counterbalancing, it has been found that the problem is not nearly as significant as that which exists in counter-balancing a single long -blade of the type employed in present day disconnect switches, and counterbalancing would be a much lower cost.

With either arrangement there is no tendency for the switchblade to move from either closed or open position of its otwn volition. Therefore the switchblades do not have to be locked by the mechanism linkage in either the open or closed position, as is found necessary in the case of -most existing switch types.

'Because the contact structures are tolerable to large variations in insulator column center lines, the switch of the type described herein is extremely easy to adjust in the field and will maintain its proper contact adjustment over substantially long periods of time.

By employing sealed pressure hinge contacts of the type described in U.S. Patent Nos. 2,673,902, 2,673,903 and 2,673,904 all assigned to the assignee of the instant invention, excellent performance in minimum maintenance characteristics at the Ehinge linkages are insured.

The switch of the instant invention has the added `advantage of being directly applicable to conventionally used switching station layouts; does not require any special arrangement of conductors nor any additional Space.

Although there has been described a preferred embodiment of this novel invention, rnany -variations and modifications will now be .apparent to t-hose skilled in the art. Therefore, this invention is to be limited, not by the specific disclosure herein, but only by the appending claims.

The embodiments of an invention in which an exclusive privilege or property is claimed are defined as follows:

1. A disconnect switch comprising a base, first and second insulator columns secured at spaced intervals on said base; first and second disconnect switch assemblies mounted upon an associated insulator column; each of said assemblies comprising first and rsecond pivot points, a switchblade and first and second links of substantially equal length; a first end of said first and second links being pivotally linked to said first and second pivot points; the second ends of said first and second links being pivotally coupled to said switchblade at spaced intervals, thereby forming a parallelogram linkage for pivoting said switchblade between an engaged and a disengaged position; the ends of said first and second disconnect switchblades closest to one another being provided with a substantially tapered point and a tulip clip, respectively, for providing suitable electrical engagement therebetween when said disconnect switch is in the engaged position.

2. The switch of claim 1 further comprising first means for simultaneously moving said first and second disconnect assembly switchblades between an engaged and disengaged position.

3. The switch of claim 1 further comprising first means for simultaneously moving said first and second disconnect 'assembly switchblades between an engaged and disengaged position; said first means comprising first and second bevel gear assemblies, first and second rotatably mounted shafts on said first and second insulator columns, first and second links having first ends coupled to said first and second shafts at the lower ends thereof; an operating arm pivotally linked to the opposite ends of said links; said first and second bevel gear assemblies coupling said first and second shafts to one link of said first and second disconnect switch assemblies for rotating said switchblades between said engaged and disengaged positions under control of said operating arm.

4. The device of claim 1 wherein said switchblade parallelogram arrangements position said switchblades substantially horizontal and parallel to one another, said switchblades moving in a vertically aligned plane between an engaged and disengaged position.

5. The device of claim 1 wherein said switchblade parallelogram arrangements position said switchblades substantially horizontal and parallel to one another, said switchblades moving in a horizontally aligned plane between an engaged and disengaged position.

No references cited.

ROBERT K. SCHAEFER, Primary Examiner.

H. HOHAUSER, Assistant Examiner. 

1. A DISCONNECT SWITCH COMPRISING A BASE, FIRST AND SECOND INSULATOR COLUMNS SECURED AT SPACED INTERVALS ON SAID BASE; FIRST AND SECOND DISCONNECT SWITCH ASSEMBLIES MOUNTED UPON AN ASSOCIATED INSULATOR COLUMN; EACH OF SAID ASSEMBLIES COMPRISING FIRST AND SECOND PIVOT POINTS, A SWITCHBLADE AND FIRST AND SECOND LINKS OF SUBSTANTIALLY EQUAL LENGTH; A FIRST END OF SAID FIRST AND SECOND LINKS BEING PIVOTALLY LINKED TO SAID FIRST AND SECOND PIVOT POINTS; THE SECOND ENDS OF SAID FIRST AND SECOND LINKS BEING PIVOTALLY COUPLED TO SAID SWITCHBLADE AT SPACED INTERVALS, THEREBY FORMING A PARALLELOGRAM LINKAGE FOR PIVOTING SAID SWITCHBLADE BETWEEN AN ENGAGED AND A DISENGAGED POSITION; THE ENDS OF SAID FIRST AND SECOND DISCONNECT SWITCHBLADES CLOSEST TO ONE ANOTHER BEING PROVIDED WITH A SUBSTANTIALLY TAPERED POINT AND A TULIP CLIP, RESPECTIVELY, FOR PROVIDING SUITABLE ELECTRICAL ENGAGEMENT THEREBETWEEN WHEN SAID DISCONNECT SWITCH IS IN THE ENGAGED POSITION. 